Film material and pattern forming process

Abstract

A film material includes a support film having a transmittance of at least 60% with respect to light of wavelength 300-450 nm, and a resin layer containing 0.001-10 wt % of a basic compound with a molecular weight of up to 10,000, and having a thickness of 1-100 μm. A pattern is formed by attaching the resin layer in the film material to a chemically amplified negative resist layer on a wafer, exposing, baking, and developing the resist layer. The profile of openings in the pattern is improved.

The invention claimed is: 
     
       1. A pattern forming process comprising the steps of:
 attaching a film material via a resin layer to a chemically amplified negative resist layer on a wafer, 
 exposing the resist layer to radiation, 
 baking the exposed resist layer, and 
 developing the baked resist layer, 
 wherein the film material comprises a support film having a transmittance of at least 60% with respect to light of wavelength 300 to 450 nm, and the resin layer disposed on one surface of the support film, the resin layer containing 0.001 to 10% by weight of a basic compound with a molecular weight of up to 10,000, and the resin layer having a thickness of 1 to 100 μm. 
 
     
     
       2. The pattern forming process of  claim 1  wherein the radiation used in the exposure step is radiation of wavelength 190 to 500 nm. 
     
     
       3. The pattern forming process of  claim 1  wherein the chemically amplified negative resist layer comprises a siloxane skeleton-containing resin with a weight average molecular weight of 3,000 to 500,000. 
     
     
       4. The pattern forming process of  claim 1  wherein the chemically amplified negative resist layer comprises
 (A) a siloxane skeleton-containing polymer represented by the formula (1) and having a weight average molecular weight of 3,000 to 500,000, 
 
       
         
           
           
               
               
           
         
       
       wherein R 1  to R 4  are each independently a C 1 -C 8  monovalent hydrocarbon group, m is an integer of 1 to 100, a, b, c and d are numbers in the range: 0≤a≤1, 0≤b≤1, 0≤c≤1, 0≤d≤1, 0<a+b≤1, and a+b+c+d=1, X is a divalent organic group of the formula (2) and Y is a divalent organic group of the formula (3): 
       
         
           
           
               
               
           
         
       
       wherein Z 1  and Z 2  are each independently a single bond or a divalent organic group selected from the following: 
       
         
           
           
               
               
           
         
       
       R 5  to R 8  are each independently a C 1 -C 4  alkyl or alkoxy group, k and h are each independently 0, 1 or 2,
 (B) a polyhydric phenol compound having at least 3 hydroxyl groups, 
 (C) a photoacid generator which is decomposed to generate an acid upon exposure to radiation of wavelength 190 to 500 nm, and 
 (D) at least one crosslinker selected from the group consisting of an amino condensate modified with formaldehyde or formaldehyde-alcohol, a phenol compound having on the average at least two methylol or alkoxymethylol groups in the molecule, and a polyhydric phenol compound having a hydroxyl group replaced by a glycidoxy group. 
 
     
     
       5. The pattern forming process of  claim 1  wherein the chemically amplified negative resist layer is formed of a resin composition comprising:
 (A) a siloxane skeleton-containing polymer represented by the formula (1) and having a weight average molecular weight of 3,000 to 500,000, 
 
       
         
           
           
               
               
           
         
       
       wherein R 1  to R 4  are each independently a C 1 -C 8  monovalent hydrocarbon group, m is an integer of 1 to 100, a, b, c and d are numbers in the range: 0≤a≤1, 0≤b≤1, 0≤c≤1, 0≤d≤1, 0<a+b≤1, and a+b+c+d=1, X is a divalent organic group of the formula (2) and Y is a divalent organic group of the formula (3): 
       
         
           
           
               
               
           
         
       
       wherein Z 1  and Z 2  are each independently a single bond or a divalent organic group selected from the following: 
       
         
           
           
               
               
           
         
       
       R 5  to R 8  are each independently a C 1 -C 4  alkyl or alkoxy group, k and h are each independently 0, 1 or 2,
 (B) a polyhydric phenol compound having at least 3 hydroxyl groups, 
 (C) a photoacid generator which is decomposed to generate an acid upon exposure to radiation of wavelength 190 to 500 nm, 
 (D) at least one crosslinker selected from the group consisting of an amino condensate modified with formaldehyde or formaldehyde-alcohol, a phenol compound having on the average at least two methylol or alkoxymethylol groups in the molecule, and a polyhydric phenol compound having a hydroxyl group replaced by a glycidoxy group, and 
 (G) a solvent. 
 
     
     
       6. The pattern forming process of  claim 1  wherein the resin layer comprises a resin selected from the group consisting of an epoxy resin, phenolic resin, acrylic resin, silicone resin, polyester resin, polyurethane resin and polyimide resin. 
     
     
       7. The pattern forming process of  claim 6  wherein the resin layer comprises a siloxane skeleton containing resin with a weight average molecular weight of 3,000 to 500,000.